Electrochemical energy storage systems, such as batteries, supercapacitors and the like, have been widely implemented for large-scale energy storage applications. Various battery designs, including flow batteries, have been adopted for this purpose. Compared to other types of electrochemical energy storage systems, flow batteries can be advantageous, particularly for large-scale applications, due to their ability to decouple the parameters of power density and energy density from one another.
Flow batteries generally include negative and positive active materials in corresponding electrolyte solutions, which are flowed separately across opposing sides of a membrane or separator in an electrochemical cell. The battery is charged or discharged through electrochemical reactions of the active materials that occur inside the cell. Existing flow batteries have suffered from their reliance on battery chemistries and cell designs that result in high cell resistance and/or active materials that cross over the membrane and mix with the opposing electrolyte solution. This phenomenon results in diminished energy storage performance (e.g., round trip energy efficiency) and poor cycle life, among other factors. Despite significant development efforts, no commercially viable flow battery technologies have yet achieved this desirable combination of properties.
In view of the foregoing, improved active materials and electrolyte solutions for electrochemical energy storage would be highly desirable. The present disclosure satisfies the foregoing needs and provides related advantages as well.